I think the atp ball is roughly 1.5 ft over the net (give or take 6 inches, this is the base shot). He feels the academy and usta ball can be useful at times but it severely limits the player if that non penetrating shot is their base shot. And rightfully so, the loopier it is the more time it gives the opponent and with time comes comfort and options. A loopier shot is neutral in the 14's, that same shot is slightly more attackable at the 16s, at the 18s it's a very attackable ball, on the futures it's a powderpuff, on the challenger tour it's a meatball, at the atp 300 - 100 rankings it's a joke, top 100 they shove it down your throat with their eyes closed 95% of the time.

It's a little degrading to the academy and usta but he is actually correct in a sense. He obviously feels that you need a penetrating ball and the academy ball is loopier (usta even loopier) and provides better consistency but it has a theoretical max plateau (and that isn't a pro with a chance at winning a grand slam).

Can't argue with a guy who has produced tracy austin, davenport, sampras, sharapova, joyce and many others.

I think this is pretty accurate assessment. poly string changed the game somewhat but the net clearance hasn't changed that much. instead the rally speed and accuracy went up compared to 10 or 20 yrs ago.